Related notes:

SMPTE ST 2067-2 (currently a Draft Publication) allows one or more OpenType font files to be packaged alongside a TTML document in a single MXF (ST 377-1) container. There is a font file associated with each referenced font family that is not a generic font family. The MXF container uses a UUID to identify each packaged font file. ST 2067-2 maps fontFamily values to UUIDs using a Type 5 UUID as specified in IETF RFC 4122.